Drain check valve and mounting means

ABSTRACT

A drain check valve using a peripheral mounting gasket compressionally loaded to bind itself against the interior of a pipe, with the maximum amount of compressive loading being fixed by a mechanical stop. A valve is guided in the unit by a guide post engaging the float internally away from liquid flow. A vent is available to communicated gases to atmosphere.

[ Oct. 30, 1973 United States Patent r191 Benke M. Cm c ."0 KT 0 O 9 l 7DRAIN CHECK VALVE AND MOUNTING MEANS 3/1965 McKel lipm... 7/1922Pavitchick [73] Assignee:

Primary ExaminerAlan Cohan 22 Filed:

Attorney-Woodling, Krost, Granger and Rust Related US. Application Data[63] Continuation-impart of Ser. No. 2,734, Jan. 20,

ABSTRACT 1970, abandoned.

A drain check valve using a peripheral mounting gasket compres'sionallyloaded to bind itself against the interior of a pipe, with the maximumamount of comk 16 "113 mF4 W0 mmm c a e ms GU SLM i UhF 1]] 2 8 555 [llpressive loading being fixed by a mechanical stop. A

285/139 346; 220/245 valve is guided in the unit by a guide postengaging the float internally away from liquid flow. A vent is availableto communicated gases to atmosphere.

[56] References Cited UNITED STATES PATENTS 1,753,724 4/l930 137/433 7Claims, 7 Drawing Figures W -i a a .N r v. k

PAIENTEDnm a 0 ms SHEET 10F 5 INVENTOR.

EAL/I25 KISS BEN/(E BY 4) 5 *w DRAIN CHECK VALVE AND MOUNTING MEANS Thisapplication is acontinuation-in-part application of U. S. Ser. No. 2,734filed Jan. 20, 1970 now abandoned.

The present invention relates to check valves for normally open drainsand is more particularly concerned with backup locks for sewer drainsand means for mounting such .valves for their. simpleinstallation andremoval.

A variety of valve designs are available as sewer backup locks andtypically include a float or float mechanism to close the drain duringflood conditions or upon stoppage and backup in the system. Certain ofthe prior designs include mounting means which make it possible toinstall the assembled .valve in ordinary pipe without dis-assembly orthe provision of specific apparatus to accommodate the valve.

However, the quick-assembly valves heretofore available have not beenentirely satisfactory. For example,

problems remain such as failure of the mounting means under extremepressure loads or because of weakening of parts of the assemblymechanism by over-stressing of either the pipe orthe mechanism duringinstallation.

Incontrast, the present invention provides a valve having a-peripheralmember which is distendable radially against the inner wall of the pipe(or other structure) in which it is to be mounted. Means are included tofix the radial pressure against the pipe within predetermined limits toprovide an adequate minimum assembly pressure while limiting thepressure in accordance with the structural limits of the pipe and theassembly.

The present invention provides a valve construction where solids andliquids encountered in the system do not normally engage the areas ofcontact between the guide and valve member and therefore do not hindermovement between the two. In this installation the construction is suchthat backed up solids and liquids do not engage and contact the valveseat but are spaced therefrom because of a trapped air column. The valveconstruction is of such a design that the normal liquid flow down thedrain will keep the valve member free of lint and other solidsaccumulation.

The preferred form of the invention is shown in the drawings, in which:t

FIG. 1 is an elevational view in section of the valve installed in apipe;

FIG. 2 is a plan view, partly cut away, on a smaller scale;

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG.. 1;

FIG. 4 is an elevational view in section of a modification of the valveof the present invention positioned in a drain pipe;

FIG. 5 is a fragmentary elevational view similar to FIG. 4 showing thevalve after being firmly secured in the drain pipe; I

FIG. 6 is a view taken generally along the line 66 of FIG. 4; and

FIG. 7 is a view taken generally along the line 7--7 of P164.

As shown in the drawings, the valve 10 is mounted in a drain pipe D andincludes a body ll having an axial main bore 12. Near the upper end ofthe bore, a ledge or wall 13 projects inwardly and terminates in a valveseat or circularaperture 14. The ledge 13 has a pluralityof recesses 15andaligned bores 16 to receive assembly bolts 17. I

The heads of bolts 17 may have any suitable wrenching form such asscrewdriver slots or the wrenchsockets 18 best seen in FIG. 2. The bolts17 engage the ledge 13 by means of steel washers l9 and cushioningwashers 20 and extend through the bores 16 and the main-bore 12 toengage" threaded apertures 21 in a compression or base plate 22. Thebolts 17 carry stops 17a, such as circlips, to prevent their inadvertantremoval from the apertures 21.

The base plate 22 has a plurality of drain apertures 23 therein andcarries a flange 24 of a diameter similar to the diameter of the valvebody 1 1. The base plate 22 also carries an upwardly projecting sleeve25 which is received in a relief bore'26 in the valve body 11. Thesleeve 25 terminates at its upper end in a shoulder 27 which meets anabutment or radial face 28 at the junction of the bores 26 and 12.

Surrounding the sleeve 25, the base plate carries a pair of rigid ringwashers 29 and 30 which are separated by a deformable gasket 31 ofrubber or similar deformable material. The washer 29 bears against baseplate flange 24 and the upper washer 30 bears against the lower edge 11aof the valve body 11. When not under compression, the outer surface ofgasket 31 may lie in the position exemplified by the dotted line 32, aswill be discussed more fully hereinafter.

The base plate 22 has a central threaded bore 33 for mounting a guidepost 34 centrally within the bore 11. The post 34 is generally square incross-section, as best seen in FIG. 3, but is relieved or rounded at itsedges 35 and at its upper corners 36.

The post 34 carries a hanger pin 37 at its upper end on which a valvemember 38 normally rests. The valve member 38 preferably takes thegeneral form of an elongated, hollow, or bell-shaped, rubber orsynthetic member fitting relatively loosely over the post edges 35.Externally, the valve member 38 is of greater diameter than the circularaperture 14' of ledge 13, so that the rounded portion of 'the valvemember can fully close that aperture, as shown in dotted lines at 39.

It is of particular importance that the guide post 34 is located withinthe valve member 38 and out of the path of drainage through the valve.This prevents any debris, such as lint,strings, or trash, from beingtrapped between the valve member and its guide. Any such trapped matterwould interfere-with the reliable operation of the valve member 38, asoccurs in prior devices which employ external guides. I

Another particularly advantageous feature of the invention is a threadedbore or vent 40 through the ledge 13 which provides for relief of gastrapped in the bore 12. With suitable riser and overflow piping (notshown) extended through the conventional screen cover 41 the vent can bepiped to any suitable place, for example exteriorly of a building withinwhich this structure is lo- '22 is positively drawn toward the ledge 13so that the compression washers 29 and 30 are forced toward each otherby the flange 24 and the lower edge 11;: of the body 11. This motion ofthe washers 29 and 30 squeeze the gasket 31 radially outwardly againstthe wall of pipe D and radially inwardly against the surface of sleeve25 to form a frictional lock therebetween.

However, the amount of radial stress placed on the pipe D and the sleeve25, as well as the possibly destructive, compressive-load on thematerial of the gasket 31, is positively limited by engagement of theshoulder 27 against the radial face 28, which prevents furthertightening of the bolts 17. Where desired, the maximum compressive-loadon the gasket 31 may be changed by a change in thickness of the washers29, 30.

This positive, dual limitation of the assembling force is of particularadvantage in this invention, espectially since the people who maintainor work with such valves often are not mechanics of the highest calibre,including both inept homeowners and low-wage laborers. The mountingmeans of the present invention provides a high degree of reliability inthat one simply tightens the bolts 17 until they refuse to turn anyfurther against the abutment of shoulder 27 and face 28. This assuresboth an adequate mounting force and a limitation of the force to preventdamage to either the pipe or the valve. Since proper maintenance of suchvalves requires periodic removal for cleaning, this advantage isrepetitive.

Once installed, the valve reacts to a backup of liquid by lifting of thevalve member 38 against the aperture or valve seat 14. Air trapped underthe bell-shaped float provides for positive lifting and closing of thevalve member 38 until the water recedes.

Where the vent bore 40 is not used, it is to be plugged in any suitablemanner. However, it is preferred to provide a vent line from the bore 40to a suitable elevation for spilling liquid or venting of gas. Forexample, in a basement drain, the vent bore 40 may be piped outside toan elevation just above the ground.

FIGS. 4 through 7 illustrate a modified form of the structure which hasbeen shown in FIGS. 1 through 3 and illustrates a variation in thepresent teachings. Shown in the drawings is a drain check valveidentified generally by the reference numeral 45 in combination with adrain which includes a sewer drain pipe 47 which has an upper open bell48 connected to a lower smaller diameter conduit by means of a shoulder50 which as seen, defines a generally horizontal surface. A fitting ring52 is positioned within the bell 48 and has its lower end portionresting on the shoulder 50 and has its opposite upper end portionterminating approximately level with the upper open end of the bell 48.The fitting ring 52 has an outer surface which is provided with arecessed wall portion 53 and the fitting ring defines what is generallyreferred to as an annular chamber 55 with the bell 48. The fitting ringalso has an inner surface which is provided with a wall thereon whichdefines a shoulder 54. The basic reason for providing the fitting ring52 is so that a consistent diameter can be provided for securing thecheck valve in the sewer drain. It will be appreciated by those skilledin the art that the inner circumferentially extending surface of thebell 48, as drain pipe are commercially constructed, is not held to avery close tolerance and so therefore in any given installation thetolerance might be such that the means for securing the check valve inthe drain would be ineffective.

The fitting ring 52 is secured in the bell 48 by means of cement 56which is provided in the annular chamber 55 and as will be seenparticularly in FIG. 5, this cement travels into the recessed wallportion 53 so as to firmly anchor the fitting ring in the positionshown. It is preferred that the cement be a special type of latex cementsince this type of cement is able to flex with temperature variations toa much higher degree than ordinary cement. This ability of the materialhelps to keep at a minimum, the internal stresses that eventuallyproduce cracks and weakening of the structure.

The check valve comprises a lower body member 58 having upper and lowerend portions 59 and 60 respectively and having a bore 61 extendingtherethrough. The upper end portion of the lower body member is providedwith a stop surface 62 and what has been referred to as a force applyingsurface 63. The lower end portion 60 of body member 58 is formed in thenature of a tripod construction having leg members 64 and fluid findsaccess to the drain by way of the openings which occur between the legmembers 64.

An upper body member 63 is provided which has upper and lower endportions 68 and 69 respectively and a bore 70 which extends therethroughand generally coaxial with the bore in the lower body member 58. Wallmeans are provided in the bore 70 of the upper body member and serve todefine a valve seat 71. The upper body member 67 like the lower bodymember 58 is also provided with a stop surface 72 and a force applyingsurface 73 and these two surfaces are located axially in line withsurfaces 62 and 63 respectively on the lower body member.

As seen in the drawings a deformable ring or gasket 78 is provided andsurrounds the lower end portion 69 of body member 67 and is locatedbetween the force applying surfaces 63 and 73. A metal washer or ring isprovided adjacent the deformable ring 78, however, the only purpose thisring accomplishes is providing the proper axial distance betweensurfaces 63 and 73. It will be appreciated by those skilled in the artthat the deformable ring can be either cut from an extruded member orcan in effect be die cast. In this particular construction the ring iscut from an extruded axial member and the tolerances can only be heldwithin certain limits. In order to achieve exactly the correct axialdimension the metal' washer 75 is provided of the cor rect thickness sothat the precise dimension is'pro-' vided. In all other respects themetal washer 75 is unnecessary. Three axially extending bolts 81 areprovided which extend through openings in the upper body member 67 andinto threaded openings in the lower body member 58. These bolts whentightened in a conventional manner serve to move the upper and lowerbody members axiallytoward each other to a position which is limited byengagement of the surfaces 62 and 72. Assembly of the upper and lowerbody members together in such'a manneras to lock the entire assembly 'inthe drain pipe will be discussed in more detail hereinafter.

The lower end portion 60 of the lower body member is provided with abase 65 from which extends a generally axially extending mount 66. Avalve guide 84 which extends in generally an axial direction is securedto the lower end portion of the lower body member by means of a threadedextension 85 being threadably received in the mount 66. As will be seenin FIG. 7 the valve guide 84 is generally square in cross section withthe corners being rounded off or radiused as at 86 so that bearingsurfaces are provided. It will be appreciated that the number of bearingsurfaces is not critical and the number'of surfaces might be more ormight be only three in number. A valve member 88 is adapted to moveaxially on the valve guide 84 between an upper closed position shown indotted lines in FIG. 4 wherein it is in engagement with the'valve seat71 so as to close the bore in the upper and lower body members and alower open position whereat liquids can readily flow through the valve.The valve member 88 is comprised of a generally cylindrically shapedmember having an open lower end 89 and a closed upper end 90. The closedupper end as shown carries generally the shape of a hemisphere whichshape is the portion of the valve member which engages the valve seat inthe closed position of the valve member. In a manner similar to FIG. 1 avent 93 is provided which may be piped or otherwise connected to theoutside of any structure within which the valve is installed and is forthe purpose of relieving the drain pipe and system closed off by closingof the valve with any sewer gases or other detrimental materials. r v Iv The check valve shown in FIGS. 4 through 7 is assembled by placingthe'parts in the position generally shown in FIG. 4 and in this positionit'will be noted the exterior circumferential surface of the deformablerubber ring 78 is spaced from the internal surface of the fitting ring52 and it will also be noted that the stop surfaces 62 and 72 are spacedfrom each other. The bolts 81 are then tightened which causes the forceapplying surfaces 63 and 73 to squeeze or compress the deformable rubberring 78 causing it to expand radially into contact with the innersurface of the fitting ring and to engage this surface below theshoulder 54. This is shown in FIG. 5. The amount of compression of thering and the amount of its radial expansion is limited by engagement ofthe stop surfaces 62 and 72. This assures that the same consistentholding effect can be accomplished each time that the check valve isplaced in the drain.

With-the check valve held in the drain pipe as shown in FIG. 5 and withthe valve member in open'position it'will be apparent that drain watersuch as drainage from washing machines, etc., can freely flow throughthe openings in both the upper and lower body members and can findaccess to the city sewer system in a conventional manner. The action ofthe liquids over the hemispherically shaped closed upper end 90 acts toconveniently cleanse this particular surface which -is a surface whichmust seat against the valve seat 71 in the closed condition of the checkvalve.

Now let it be assumed that the sewer system becomes incapable ofhandling a given flow of liquid and the liquid backs up in the drainpipe 47 and toward the basement floor of a residence. The action of theliquid backing up the drain pipe causes air trapped within the confinesof the valve member 88 to be compressed, thereby lifting the valvemember 88 into the closed position which is indicated by the dottedlinesin FIG. 4. The valve member is held in this closed conditionessentially by means of a trapped column of air between the uppersurface of the liquid and the inside surface of the closed upper end 90of the=valve member. Assuming the vent 93 is piped or otherwiseconnected to some other location, any excess liquid pressure or sewergases will be transmitted through the vent 93 and by way of this piping.Assuming that the vent has been closed by a pipe plug because of theinability or undesirability of connecting the same otherwise, it will beseen that a column of air is also trapped in the bore of the lower bodymember which will keep solids and liquids from reaching the valve seat71. 7

The material of construction of the valve member is preferably a rigidpolyvinyl chloride material so that sufficient rigidity is given to thismember and the outer surface of the closed upper end 90 is preferablycoated with a neoprene type rubber which is sufficiently flexible toprovide for good sealing on the valve seat but which will readilyrelease 'when the valve member should move to its open position. Ashoulder 91 is provided in the interior of the closed upper end 90 andis for the purpose of engaging the top of the valve guide 84 to limitthe downward movement of the valve member when it moves to openposition.

It will therefore be appreciated by those skilled in the 7 art that thepresent drain check valve and particularly the check valve shown anddescribed in FIGS. 4 through 7 is extremely well designed toconveniently fit into, be installed in and be removed from presentlyexisting sewer drain pipe which conventionally exists in present homesand other installations. The assembly is adapted for convenientinstallationand once installed the check valve can be removed from thedrain pipe for cleaning or for whatever reason might be desired. Many ofthe prior art devices which have been designed are so extremelycomplicated as to be virtually impossible to install, and then onceinstalled, result in a permanent installation which cannot be removedwithout tearing up a substantial part of the floor within which thedevice is installed. The use of the fitting ring 52 provides a means ofinstalling the check valve of the present invention in conventionaldrain pipe and provides that consistent holding power is utilized insecuring the assembly in position within the necessity of utilizing askilled workman for the installation. The particular and specific designof the valve member and the valve guide upon which it travels provides aconstruction which is kept free of the liquid and solids which maytravel through the valve assembly'and this results in longevity and goodworking of the entire assembly.,When the vent 93 is maintained in aclosed position the liquids and solids which the check valve is adaptedto prevent from passing back through the entrance of the device are alsokept off of the sealing surfaces of the valve member and the valve seat.Other advantages will be apparent to those skilled in the art afterreviewing the present disclosure. 7

Although this invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure-of the preferred form has been made only by way of exampleand that numerous changes in'the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:

l. A drain check valve in a drain combination including a sewer drainpipe having an upper open bell portion connected to a lower smallerdiameter conduit portion by a shoulder defining a surface, a fittingring having one end portion resting on said surface and havbell portion,said fitting ring having an inner surface having a wall thereon defininga shoulder, cement in said annular chamber and in said recessed wallportion of said fitting ring to hold said fitting ring fixedly inposition, said check valve comprising a lower body member having upperand lower end portions and having a bore extending therethrough, saidupper end portion of said lower body member having a stop surface and aforce applying surface thereon, an upper body member having upper andlower end portions and having a bore extending therethrough generallycoaxially with said bore in said lower body member, wall means in saidupper body member bore defining a valve seat, said lower end portion ofsaid upper body member having a stop surface and a force applyingsurface thereon axially in line respectively with said stop surface andsaid force applying surface on said lower body member, a deformable ringsurrounding said lower end portion of said upper body member and locatedbetween said force applying surfaces on said upper and lower bodymembers respectively, a plurality of generally axially extending boltsextending between said upper and lower body members and in tightenedcondition axially pulling said body members together and axiallycompressing said ring between said two force applying surfaces causingit to radially expand into contact with said inner surface of saidfitting ring below said shoulder thereon, said two stop surfaceslimiting axial movement of said body members and radial expansion ofsaid ring, an axially extending valve guide secured to said lower endportion of said lower body member, a valve member movable on said valveguide between an upper closed position in engagement with said valveseat and a lower open position, said valve member comprising a generallycylindrically shaped member having an open lower end and a closed upperend, said closed upper end including a hemispherically shaped wall whichengages said valve seat in said closed position of said valve member,and a vent opening in said upper body for providing communication fromsaid bore of said lower body member to atmosphere.

2. A drain check valve in a drain combination including a sewer drainpipe having an upper open bell portion connected to a lower smallerdiameterconduit portion by a shoulder defining a surface, a fitting ringhaving one end portion resting on said surface and having another endportion terminating approximately level with said upper open bellportion, said fitting ring having an outer surface defining an annularchamber with said upper open bell portion, said fitting ring having aninner surface, cement in said annular chamber to hold said fitting ringfixedly in position, said check valve comprising a lower body memberhaving a bore extending therethrough, said lower body member having astop surface and a force applying surface thereon, an upper body memberhaving a bore extending therethrough generally coaxial with said bore insaid lower body member, wall means in said upper body member boredefining a valve seat,- said upper body member having a stop surface anda force applying surface thereon axially in line respectively with saidstop surface and said force applying surface on said lower body member,a deformable ring surrounding one of said upper and lower body membersand located between said force applying surfaces on said upper and lowerbody members respectively, a plurality of bolts extending between saidupper and lower body members and in tightened condition axially pullingsaid body members together and axially compressing said ring betweensaid two force applying surfaces causing it to radially expand intocontact with said inner surface of said fitting ring, said two stopsurfaces limiting axial mvoement of said body members and radialexpansion of said ring, a valve guide secured to said lower body member,a valve member movable on said valve guide between an upper closedposition in engagement with said valve seat and a lower open position,said valve member comprising a generally cylindrically shaped memberhavig an open lower end and a closed upper end, said closed upper endincluding a hemispherically shaped wall which engages said valve seat insaid closed position of said valve member.

3. A drain check valve comprising a lower body member having upper andlower end portions and having a bore extending therethrough, said upperend portion of said lower body member having a stop surface and a forceapplying surface thereon, an upper body member having upper and lowerend portions and having a bore extending therethrough generally coaxialwith said bore in said lower body member, one of said upper end portionof said lower body member and said lower end portion of said upper bodymember comprising an unthreaded counterbore and the other comprising anunthreaded extension fitting within said unthreaded counterbore, wallmeans in said upper body member bore defining a valve seat, said lowerend portion of said upper body member having a stop surface and a forceapplying surface thereon axially in line respectively with said stopsurface and said force applying surface on said lower body member, adeformable ring surrounding said lower end portion of said upper bodymember and located between said force applying surfaces on said upperand lower body members respectively, a plurality of generally axiallyextending bolts extending between said upper and lower body members andin tightened condition axially pulling said body members together andaxially compressing said ring between said two force applying surfacescausing it to radially expand, said two stop surfaces, limiting axialmovement of said body members and radial expansion of said ring, anaxially extending. valve guide secured to said lower end portion of saidlower body member, a valve member movable on said valve guide between anupper closed position in engagement with said valve seat and a loweropen position, said valve member comprising a generally cylindricallyshaped member having an open lower end and a closed upper end, saidclosed upper end including a hemispherically shaped wall which engagessaid valve seat in said closed position of said valve member,and a ventopening in said upper body member for providing communication from saidbore of said lower body member to atmosphere.

.4. A drain check valve comprising a lower body member having a boreextending therethrough, said lower body member having a stop surface anda force applying surface thereon, an upper body member having a boreextending therethrough generally coaxial with said bore in said lowerbody member, one of said lower body member and said upper body membercomprising an unthreaded counterbore and the other comprising anunthreaded extension fitting within said unthreaded counterbore, wallmeans in said upper body member bore defining a valve seat, said upperbody member having a stop surface anda force applying surface thereonaxially'in line respectively with said stop surface and said forceapplying surface on said lower body member, a deformable ringsurrounding one of said upper and lower body members and located betweensaid force applying surfaces on said upper and lower body membersrespectively, a plurality of bolts extending between said upper andlower body members and in tightened condition axially pullingsaid bodymembers together and axially compressing said ring between said twoforce applying surfaces causing it to radially expand, said two stopsurfaces limiting axial movement of said body members and radialexpansion of said ring, a valve guide secured to said lower body member,a valve member movable on said valve guide between an upper closedposition in engagement with said valve seat and a lower open position,said valve member comprising a generally cylindrically shaped memberhaving an open lower end and a closed upper end, said closed upper endincluding a hemispherically shaped wall which engages said valve seat insaid closed position of said vlave 5. A drain check valve comprising abody having a bore therein, a valve seat in said bore, a valve mountingmember in said bore, said valve mounting member having at least threespaced and axially extending bearing surfaces, a valve member adapted toclose against said valve seat, said valve member comprising a cylindri-I level with said upper open bell portion, said fitting ring having anouter surface defining an annular chamber with said upper open bellportion, said fitting ring havcally shaped hollow member having an openlower end to fit over said valve mounting member whereby said valvemember is guided between open and closed positions on said bearingsurfaces on said valve mounting member, said cylindrically shaped hollowmember having a closed airtight upper end which has an outer convexsurface adapted to engage said valve seat in said closed position ofsaid valve member, mounting means for securing the body against asurrounding structure including a deformable gasket, means forcompressing said gasket longitudinally with respect to said bore tocause deformation thereof radially with respect to said bore, and stopmeans to limit the compression of said gasket to a predetermined value.

6. A drain check valve as claimed in claim 5, wherein said means forcompressing said gasket comprises said body having two separate partswith opposed facing ing an inner surface, means in said annular chamberto hold said fitting ring fixedly in position, said check valvecomprising a lower body member having a bore extending therethrough,said lower body member having a stop surface and a force applyingsurface thereon, an upper body member having a bore extendingtherethrough generally coaxial with said bore in said lower body member,wall means in said upper body member bore defining a valve seat, saidupper body member having a stop surface and a force applying surfacethereon axially in line respectively with said stop surface and saidforce applying surface on said lower body member, a deformable ringsurrounding one of said upper and lower body members and located betweensaid force applying surfaces on said upper and lower body membersrespectively, a plurality of bolts extending between said upper andlower body members and in tightened condition axially pulling said bodymembers together and axially compressing said ring between said twoforce applying surfaces causing it to radially expand into contact withsaid inner surface of said fitting ring, said two stop surfaces limitingaxial movement of said body members and radial expansion of said ring, avalve guide secured to said lower body member, a valve member movable onsaid valve guide between an upper closed position in engagement withsaid valve seat and a lower open position, said valve member comprisinga generally cylindrically shaped member having an open lower end and aclosed upper end, said closed upper end including a hemisphericallyshaped wall which engages said valve seat in said closed position ofsaid valve member.

1. A drain check valve in a drain combination including a sewer drainpipe having an upper open bell portion connected to a lower smallerdiameter conduit portion by a shoulder defining a surface, a fittingring having one end portion resting on said surface and having anotherend portion terminating approximately level with said upper open bellportion, said fitting ring having an outer surface having a recessedwall portion and defining an annular chamber with said upper open bellportion, said fitting ring having an inner surface having a wall thereondefining a shoulder, cement in said annular chamber and in said recessedwall portion of said fitting ring to hold said fitting ring fixedly inposition, said check valve comprising a lower body member having upperand lower end portions and having a bore extending therethrough, saidupper end portion of said lower body member having a stop surface and aforce applying surface thereon, an upper body member having upper andlower end portions and having a bore extending therethrough generallycoaxially with said bore in said lower body member, wall means in saidupper body member bore defining a valve seat, said lower end portion ofsaid upper body member having a stop surface and a force applyingsurface thereon axially in line respectively with said stop surface andsaid force applying surface on said lower body member, a deformable ringsurrounding said lower end portion of said upper body member and locatedbetween said force applying surfaces on said upper and lower bodymembers respectively, a plurality of generally axially extending boltsextending between said upper and lower body members and in tightenedcondition axially pulling said body members together and axiallycompressing said ring between said two force applying surfaces causingit to radially expand into contact with said inner surface of saidfitting ring below said shoulder thereon, said two stop surfaceslimiting axial movement of said body members and radial expansion ofsaid ring, an axially extending valve guide secured to said lower endportion of said lower body member, a valve member movable on said valveguide between an upper closed position in engagement with said valveseat and a lower open position, said valve member comprising a generallycylindrically shaped member having an open lower end and a closed upperend, said closed upper end including a hemispherically shaped wall whichengages said valve seat in said closed position of said valve member,and a vent opening in said upper body member for providing communicationfrom said bore of said lower body member to atmosphere.
 2. A drain checkvalve in a drain combination including a sewer drain pipe having anupper open bell portion connected to a lower smaller diameter conduitportion by a shoulder defining a surface, a fitting riNg having one endportion resting on said surface and having another end portionterminating approximately level with said upper open bell portion, saidfitting ring having an outer surface defining an annular chamber withsaid upper open bell portion, said fitting ring having an inner surface,cement in said annular chamber to hold said fitting ring fixedly inposition, said check valve comprising a lower body member having a boreextending therethrough, said lower body member having a stop surface anda force applying surface thereon, an upper body member having a boreextending therethrough generally coaxial with said bore in said lowerbody member, wall means in said upper body member bore defining a valveseat, said upper body member having a stop surface and a force applyingsurface thereon axially in line respectively with said stop surface andsaid force applying surface on said lower body member, a deformable ringsurrounding one of said upper and lower body members and located betweensaid force applying surfaces on said upper and lower body membersrespectively, a plurality of bolts extending between said upper andlower body members and in tightened condition axially pulling said bodymembers together and axially compressing said ring between said twoforce applying surfaces causing it to radially expand into contact withsaid inner surface of said fitting ring, said two stop surfaces limitingaxial movement of said body members and radial expansion of said ring, avalve guide secured to said lower body member, a valve member movable onsaid valve guide between an upper closed position in engagement withsaid valve seat and a lower open position, said valve member comprisinga generally cylindrically shaped member having an open lower end and aclosed upper end, said closed upper end including a hemisphericallyshaped wall which engages said valve seat in said closed position ofsaid valve member.
 3. A drain check valve comprising a lower body memberhaving upper and lower end portions and having a bore extendingtherethrough, said upper end portion of said lower body member having astop surface and a force applying surface thereon, an upper body memberhaving upper and lower end portions and having a bore extendingtherethrough generally coaxial with said bore in said lower body member,one of said upper end portion of said lower body member and said lowerend portion of said upper body member comprising an unthreadedcounterbore and the other comprising an unthreaded extension fittingwithin said unthreaded counterbore, wall means in said upper body memberbore defining a valve seat, said lower end portion of said upper bodymember having a stop surface and a force applying surface thereonaxially in line respectively with said stop surface and said forceapplying surface on said lower body member, a deformable ringsurrounding said lower end portion of said upper body member and locatedbetween said force applying surfaces on said upper and lower bodymembers respectively, a plurality of generally axially extending boltsextending between said upper and lower body members and in tightenedcondition axially pulling said body members together and axiallycompressing said ring between said two force applying surfaces causingit to radially expand, said two stop surfaces, limiting axial movementof said body members and radial expansion of said ring, an axiallyextending valve guide secured to said lower end portion of said lowerbody member, a valve member movable on said valve guide between an upperclosed position in engagement with said valve seat and a lower openposition, said valve member comprising a generally cylindrically shapedmember having an open lower end and a closed upper end, said closedupper end including a hemispherically shaped wall which engages saidvalve seat in said closed position of said valve member, and a ventopening in said upper body member for providing communication from saidbore of said lower body member to atmosphere.
 4. A drain check valvecomprising a lower body member having a bore extending therethrough,said lower body member having a stop surface and a force applyingsurface thereon, an upper body member having a bore extendingtherethrough generally coaxial with said bore in said lower body member,one of said lower body member and said upper body member comprising anunthreaded counterbore and the other comprising an unthreaded extensionfitting within said unthreaded counterbore, wall means in said upperbody member bore defining a valve seat, said upper body member having astop surface and a force applying surface thereon axially in linerespectively with said stop surface and said force applying surface onsaid lower body member, a deformable ring surrounding one of said upperand lower body members and located between said force applying surfaceson said upper and lower body members respectively, a plurality of boltsextending between said upper and lower body members and in tightenedcondition axially pulling said body members together and axiallycompressing said ring between said two force applying surfaces causingit to radially expand, said two stop surfaces limiting axial movement ofsaid body members and radial expansion of said ring, a valve guidesecured to said lower body member, a valve member movable on said valveguide between an upper closed position in engagement with said valveseat and a lower open position, said valve member comprising a generallycylindrically shaped member having an open lower end and a closed upperend, said closed upper end including a hemispherically shaped wall whichengages said valve seat in said closed position of said valve member. 5.A drain check valve comprising a body having a bore therein, a valveseat in said bore, a valve mounting member in said bore, said valvemounting member having at least three spaced and axially extendingbearing surfaces, a valve member adapted to close against said valveseat, said valve member comprising a cylindrically shaped hollow memberhaving an open lower end to fit over said valve mounting member wherebysaid valve member is guided between open and closed positions on saidbearing surfaces on said valve mounting member, said cylindricallyshaped hollow member having a closed airtight upper end which has anouter convex surface adapted to engage said valve seat in said closedposition of said valve member, mounting means for securing the bodyagainst a surrounding structure including a deformable gasket, means forcompressing said gasket longitudinally with respect to said bore tocause deformation thereof radially with respect to said bore, and stopmeans to limit the compression of said gasket to a predetermined value.6. A drain check valve as claimed in claim 5, wherein said means forcompressing said gasket comprises said body having two separate partswith opposed facing surfaces on either side of said deformable gasket,and means acting between said two separate parts to move the same towardeach other.
 7. A drain check valve in a drain combination including asewer drain pipe having an upper open bell portion connected to a lowersmaller diameter conduit portion by a shoulder defining a surface, afitting ring having one end portion resting on said surface and havinganother end portion terminating approximately level with said upper openbell portion, said fitting ring having an outer surface defining anannular chamber with said upper open bell portion, said fitting ringhaving an inner surface, means in said annular chamber to hold saidfitting ring fixedly in position, said check valve comprising a lowerbody member having a bore extending therethrough, said lower body memberhaving a stop surface and a force applying surface thereon, an upperbody member having a bore extending therethrough generally coaxial withsaid bore in said lower body member, wall means in said upper bodymember bore defining a valve seat, said upper body member having a stopsurface and a force appLying surface thereon axially in linerespectively with said stop surface and said force applying surface onsaid lower body member, a deformable ring surrounding one of said upperand lower body members and located between said force applying surfaceson said upper and lower body members respectively, a plurality of boltsextending between said upper and lower body members and in tightenedcondition axially pulling said body members together and axiallycompressing said ring between said two force applying surfaces causingit to radially expand into contact with said inner surface of saidfitting ring, said two stop surfaces limiting axial movement of saidbody members and radial expansion of said ring, a valve guide secured tosaid lower body member, a valve member movable on said valve guidebetween an upper closed position in engagement with said valve seat anda lower open position, said valve member comprising a generallycylindrically shaped member having an open lower end and a closed upperend, said closed upper end including a hemispherically shaped wall whichengages said valve seat in said closed position of said valve member.